Editing Macintosh Quadra 900 (section)

== Memory and Storage ==

=== RAM Configuration ===

The Quadra 900 has 16 30-pin SIMM slots supporting 80 ns RAM modules. RAM must be installed in groups of four identical SIMMs. Apple officially supported 64 MB, but third-party configurations achieved 256 MB using sixteen 16 MB SIMMs.<ref>{{cite web |url=https://en.wikipedia.org/wiki/Macintosh_Quadra_900 |title=Macintosh Quadra 900 |publisher=Wikipedia |access-date=2026-02-10}}</ref>

Standard configuration shipped with 4 MB of RAM.

=== ROM and System Software ===

The Quadra 900 includes a 1 MB ROM. It shipped with System 7.0.1 and supports Mac OS versions up to 8.1. It is the earliest Macintosh model capable of running Mac OS 8.

=== Storage Systems ===

The system uses a SCSI interface for storage. Factory configurations included either no hard drive, a 160 MB, or a 400 MB SCSI hard drive. A 1.44 MB SuperDrive floppy drive is standard.

A front-facing 5.25" drive bay is available for a CD-ROM drive, tape backup, or SyQuest drive. Two additional internal 5.25" bays are available (three if no hard drive is installed).